clojure不能在不同的命名空间中定义相同的函数？不可能

Question

我有一个文件"map_reduce2.clj“和另一个"map_reduce3.clj"，这两个函数都是”映射-减少“它们自己。

现在我想在"map_reduce2.clj“中使用"map_reduce3.clj”的命名空间，但是当我在emacs中按下“C”来编译"map_reduce3.clj“时，

错误发生：“解析行已经指的是：#‘第12章，映射-还原2/命名空间中的解析行:第12章，映射-还原3”，但这没有任何意义。

; map_reduce3.cli
(ns chapter12.map-reduce3
  (:use clojure.java.io)
  (:require [chapter12.map-reduce2 :as c12]))

(def IGNORE "_")

(defn parse-line [line]
  (let [tokens (.split (.toLowerCase line) " ")]
    [[IGNORE (count tokens)]]))

(defn average [numbers]
  (/ (apply + numbers)
     (count numbers)))

(defn reducer [combined]
  (average (val (first combined))))

(defn average-line-length [filename]
  (c12/map-reduce parse-line reducer (line-seq (reader filename))))


; map_reduce2.clj
(ns chapter12.map-reduce2
  (:use clojure.java.io))

(defn combine [mapped]
  (->> (apply concat mapped)
       (group-by first)
       (map (fn [[k v]]
              {k (map second v)}))
       (apply merge-with conj)))

(defn map-reduce [mapper reducer args-seq]
  (->> (map mapper args-seq)
       (combine)
       (reducer)))

(defn parse-line [line]
  (let [tokens (.split (.toLowerCase line) " ")]
    (map #(vector % 1) tokens)))

(defn sum [[k v]]
  {k (apply + v)})

(defn reduce-parsed-lines [collected-values]
  (apply merge (map sum collected-values)))


(defn word-frequency [filename]
  (map-reduce parse-line reduce-parsed-lines (line-seq (reader filename))))

错误的图像

Answer 1

这可能意味着您有肮脏的REPL状态。也许您将函数parse-line从一个名称空间移到另一个命名空间。我建议重新启动REPL，或者将parse-line从map-reduce3：如何从另一个命名空间卸载函数？卸载。